Although Kanye did not attend the affair, Justin Bieber did, arriving with a group of about 7-10 people including security.

A source tells E! News Justin was joking with friends like Tyler the Creator and Lil Twist during the party. Clearly getting into it, Biebs danced and even got on the mic at one point and said, "Turn this up!"

Bieber is such a fan, he then tweeted: "Fact. @kanyewest new album is the truth."

Kourtney Kardashian's beau Scott Disick was also in attendance. The Lord came in and out of a blocked-off area during the party. He was seen hanging out, just chatting with others casually. Meanwhile outside of the building on the wall, Kanye's American Psycho film premiered, which stars Scott.